The primary objective of this contract is to support two assay techniques that will contribute towards the development of biological screening tools (state markers) which can, with good sensitivity and specificity, identify problem drinkers, and begin to develop diagnostic "trait" markers which provide biological information on genetically determined predisposing and protective factors in the development of alcoholism. The specific assay techniques are: (1) DNA extraction and PCR-based quality control conducted on 400 blood samples; and (2) adenylyl cyclase assays on 758 samples that have been collected on ISBRA/WHO study subjects.